He was a cousin and from 1790 the brother-in-law of the traveller, author and collector General Sir George Cockburn of Shanganagh Castle, County Dublin.

[2] On arrival, Drummond immediately halted all withdrawals and mounted an attack on the American side of the Niagara River.

[2] On 30 December, Riall again crossed the Niagara River further south, and repeated the deliberate destruction at Buffalo and Black Rock, although here there were a Navy yard and several other legitimate military targets.

Riall's tactics might have been correct had he faced American militia, as he thought, but were disastrous against Scott's well-trained regulars.

Riall was severely wounded in the arm early in the battle, and while riding to the rear, was captured by American infantry.

While he was a prisoner, a fellow captive (Canadian militia dragoon officer William Hamilton Merritt) described him as "very brave, near sighted, rather short, but stout."